Stay-bolt structure for boilers.



B.E. D. STAFFORD & E. l. DODDS.

STAY BOLT STRUCTURE FOR BOILERS.

APPLICATION FILED FEB. 29, I916.

Patented Oct, 17, 1916.

m A i/ 1 INVENTORS W/ NESSES srarns Anr ounron.

BENJAMIN E. D. STAFFORD AND ETHAN I. DOIDDS, OF PITTSBURGH, PENNSYLVANIA, ASSIGNORS TO FLANNERY BOLT COMPANY, OF PITTSBURGH, PENNSYLVANIA.

STAY-BOLT STRUCTURE FOR BOILERS.

Application filed February 29, 1916. Serial No. 81,258.

To all whom it may concern Be it known that we, BENJAMIN E. D. STAFFORD and ETHAN I. DoDDs, citizens'of the United States, and residents of Pittsburgh, in the county of Allegheny and State vof Pennsylvania, have invented certain new and useful Improvements in Stay Bolt the inside boiler sheet as little as possible to keep open at all times the tell-tale hole in the outer portion of a stay bolt having a spherical head, to insure against leakage past the outer end of the bolt, and to provide,

for universal movement or play of the bolt.

With these and other objects in view, the invention consists in certain novel features of construction and combinations of parts'as hereinafter set forth and pointed out'in the claims.

The accompanying drawing is a view partly in section and partly in elevation showing an embodiment of our invention.

1 represents an inner boiler sheet and 2 an outer boiler sheet, the latter being made with a hole 3, a portion of the wall of which forms a partly spherical seat 4. A stay bolt 5 is secured at one end to the inner boiler sheet 1 and the headed outer end of said bolt passes through the hole 3 in the outer boiler sheet. In the construction shown in the drawing, the head 6 of the bolt is made spherical and provided with a driving slot 7. A tell-tale hole 8 is formed in the outer portion of the bolt and is in free communication with said driving slot 7.

The inner portion of the bolt head 6 has a bearing against an annular member or gland 9, the inner portion of which projects into the hole in the boiler plate 2 so as to be disposed between the bolt head and the seat 4 and is retained in, contact with said bolt head at all times by the action of a bowed flange 10 made integral with the member 9 and forming a part of the same, the free edge of said bowed flange being somewhat enlarged, forming a seat 11 resting against the outer face of the boiler sheet 2 and welded thereto,

as indicated at 12. The bowed flange 10 also forms a chamber in which stifi' grease or other lubrlcant may be placed to prevent the accumulation of scale within the gland. The gland or member 9 projects beyond the bowedflange 10 and is threaded exteriorly to recelve the threaded flange 13 of an annular cap 14- This cap is made with an inwardly pro ecting enlargement 15 at its inner edge which bears upon a gasket 16 of copper, Babbitt metal or other suitable mater1al. The gasket is approximately triangular 1n cross section and is retained in the space between the bolt head and the gland by pressure of the depending portion 15 of the cap 14.

When the boiler is cold, the gland or yield mg member will hug the bolt head and there Wlll be a clearance space 17 between said Specification of Letters Patent. I Pate t d O t 17 1916 V gland and the seat 4 in the boiler sheet 2 as the yielding action of the member 9 will perm 1t a movement of the boiler sheets equal to wldth of the space or gap 17 with the gland closely engaging the bolt head. Such connectlon between the bolt head and the gland is augmented by the gasket 16 which is in turn held in position by the cap 14:.

It will be observed that the end of the bolt with its tell-tale hole is always exposed for inspection and that the whole structure af fords a slot which will insure lateral as well as longitudinal play or movement of the bolt without permitting any leakage of steam or water. With our improvements, removal of the cap for inspection purposes isnot necessary, and if one of the bolts should become broken, it may be withdrawn after first removing the cap and gasket and without disturbing the yielding member or gland. Furthermore, with our improvements, resistance to the movements of the boiler sheets (especially the inner sheet) due to the natural expansion and contraction of the same during the varied conditions incident to the operation of boilers, will be reduced to a minimum.

Various slight changes might be made in the details of construction of our invention without departing from the spirit thereof or limiting its scope and hence we do not wish to restrict ourselves to the precise details herein set forth except as defined by the scope of theappended claims.

Having fully described our invention,

' what we claim as new and'desire to secure by Letters-Patent, is

p 1. Ina stay bolt structure, an annular yieldmgmember constructedto engage the inner portion of the rounded head of a stay bolt and having a part to engage and to be secured to the outer face of a boiler sheet.

. 2. In a stay bolt structure, a yielding memberto embrace the rounded head of a stay bolt and to be disposed between said head and a seat in the boiler sheet through which the -bolt projects, saidyielding lnember having roundedfaceof a stay bolt head and having a part to rest against and to be secured to the outer face of an outer boiler sheet, a gasket encircling the bolt head and disposed between the same and the yielding member, and

3 an annular cap secured to said yielding member andengaglng sald gasket.

4. In astay bolt structure, the combination with a boiler sheet having a-bolt hole .forminga seat, and a stay bolt having a rounded head, of a yielding member secured to the outer face of the boiler sheet and having a part pro]ect1ng into said bolt hole and engaging the inner portionof the rounded:

head of the bolt,'said yielding member being movable with the bolt head relatively to the seat in the boiler sheet.

5. In a stay bolt structure, the combination with a boiler sheet having a bolt hole and a stay bolt passing through said hole and having a rounded head, of a yielding member havinga part engaging the inner portion of;

the rounded bolt head, said yielding member also having apart welded to said boilersheet, a gasket interposed between the bolt head and yielding member, and an annular cap thread: ed on said yielding member and engaging said gasket.

In testimony whereof, we have signed this specification in the presence of two subscribing witnesses.

. BENJAMIN E. D. STAFFORD.

ETI-IAN I. DODDS. Witnesses:

F. H. ALmsoN, EDWIN S. RYoE.

Copies 01 this patent may be obtained for five centseach, by addressing the Commissioner of Patents.

Washington, D. O. 

